Speech inputs are often used to perform various operations on an electronic device. For example, some mobile telephones or other computing devices allow users to provide voice commands or to provide other speech inputs to perform operations, indicate user selections, launch applications, or initiate communications using the mobile telephone. A speech input of a user can be detected by a microphone of a computing device and processed by an automated speech recognizer.
An automated speech recognizer may use an acoustic model and a language model to perform speech recognition. The automated speech recognizer may use the acoustic model to determine relationships between an audio signal and phonetic units in the language of the user. The language model indicates likely phonetic or word sequences for the language of the user. Using these two models, the automated speech recognizer may generate candidate transcriptions of a speech input.